When I boot normally, I only see the Xiaomi logo (both partitions)
When going to recovery, I don''t see any files at all
When I go to recovery and choose adb sideload, my computer sees nothing.
When I try to make a backup, I get the message "Can't mount /system"!
When I go to fastboot and type adb devices on my computer, there are no devices attached

How can I fix this?
Can I for example do fastboot flash zip with one of the ROMs of this forum? I have CWM with TDB on